Enantioselective Synthesis of Complex Carbocycles by C–H Insertion of Aryl/Aryl Carbenes

A range of benzene and indole-fused carbocyclic molecules were accessed by the enantioselective C–H insertion of rhodium aryl/aryl carbenes. 1,4, 1,5, and 1,6 C–H insertion reactions are chemoselective for insertion into carbon centers appended with an electron-donating heteroatom. Examples include a range of ethers, a free hydroxyl group, and a range of nitrogen substituents, including basic amines. DFT calculations support a stepwise mechanism of this process and provide insight into the origin of both stereoselectivity and the preference for C–H versus O–H insertion.